West Nile Virus May Be Culprit In Death Of Umatilla Horse

A horse near Umatilla may have died from the West Nile virus, Lake County health officials said Tuesday.

Of three tests on the horse, named Echo, one came back positive for the mosquito-borne virus, while two came back negative, said Kevin Lenhart, a Lake County Health Department spokesman.

Health officials are sending the test results and medical records to state Department of Agriculture officials for review.

However, officials there only will say they "presume" West Nile was the cause of death, and they will not be able to say so conclusively, Lake County health officials said.

"It's not a confirmed case of West Nile," Lenhart said. "Ideally, if the horse were still alive, we would be able to run additional tests. Unfortunately the horse has passed."

Echo died on Oct. 16, said Cindy Thibodeau, the quarter horse's owner.

Thibodeau, who lives on Thomas Boat Landing Road, said she was only aware of one initial test, which came back positive.

"We have been in contact quite a bit with mosquito control," she said. "I have three other horses, and it scares the hell out me."

Although the first test was positive, health officials said false positives are very common during initial testing.

"One-third of those first results are usually false positive," Lenhart said.

Meanwhile, at least eight horses in Lake County are being tested for West Nile virus -- five in the Umatilla area and one each in Lady Lake, the Sugarloaf area and Sorrento.

"All but two are near Marion County," Lenhart said.

Lake County stepped up mosquito-spraying efforts in August, after a bird and a horse in Marion County tested positive for West Nile, and health officials say spraying has been beefed up in the areas where horses are being tested.

All of the horses are being checked for West Nile and a similar virus that causes Eastern equine encephalitis, in addition to other viruses.

Test results were initially expected back in five to 10 days. Officials say they are taking longer because there is a backlog at a Kissimmee laboratory that does preliminary testing. More than 200 horses statewide are being tested.

It is up to veterinarians to report tests. They are only required to report positive results, Lenhart said.

"We don't have direct contact with the lab," he said. "We probably don't hear anything if it comes back negative."

After the initial test on Echo came back positive, more blood samples were sent to the National Veterinary Service Laboratory in Ames, Iowa, for further testing.

Because one test was positive and another was negative, officials "cannot confirm it as West Nile virus," Lenhart said.

Thibodeau said four other horses on her road are being tested for West Nile virus.

"There are probably 40 or so horses on my road within five miles," she said.

One horse near her home was euthanized after it got sick, she said.

"It was a very, very old horse and they did not treat the horse," she said. "No blood tests were done because they opted to put the horse down."

Symptoms of West Nile in a horse include a loss of control of the hindquarters, trouble standing, a droopy bottom lip and lack of appetite.

Thibodeau first noticed that Echo's lip had been twitching. The horse's veterinarian, Linda Galbraith, started treatment that day.

"She was under treatment for about 12 days," Thibodeau said.

But several IV bags of antibiotics, as well as other medication, including steroids, were unsuccessful.

"She just went down and couldn't get back," Thibodeau said.

Most of her neighbors have since begun West Nile vaccinations on their horses, but owners are still worried because they must wait three weeks after an initial vaccination before a second one is administered.

More than 110 horses in Florida have tested positive this year for West Nile. Since June, 358 birds and nine people have been infected in Florida.

The virus is spread by mosquitoes to people, birds and other animals. It produces symptoms of encephalitis, an inflammation of the brain that causes fever, headache and disorientation, among other symptoms.

In Lake County, more than 100 birds have been tested during this mosquito season, and all have come back negative.

Health officials urge people to reduce their chance of infection by staying indoors at dusk and dawn and using an insect repellent with the chemical DEET.